1. Field of the Invention
The present invention is directed to systems and methods for documenting, recording, and interpreting of the pupillary light reflex and the corneal light reflex eye screening tests in infants and young children.
2. Description of the Related Art
The coaxial ocular fundus reflex (pupillary light reflex test) has been known and taught widely to pediatricians and ophthalmologists as a diagnostic test since the early 1960's. See Roe L D, Guyton D L. The light that leaks: Bruckner and the red reflex. Surv Ophthalmol 1984; 28: 665-70, incorporated by reference herein. Light entering the human eye generates a red pupillary light reflex by traveling through the clear ocular media (i.e., the cornea, aqueous humor, lens, and vitreous body) and being reflected back out of the eye. A normal red reflex requires clarity of all ocular focusing elements.
The red pupillary reflex is generated in the following way. Normally, light reaches the transparent retina and is reflected back out of the pupil by the choroid, which is a layer of blood vessels and pigmented cells that nourish the overlying retina. The color imparted to the light reflected back out of the pupil and seen by an observer or instrument that is coaxial to the incident of the entry light is determined by the blood and the amount of pigment in the choroid. Because blood is red and pigment is brown or black, the reflected light will be red (modified by the amount of dark pigment also present). The amount of pigment present in the choroid is correlated with the amount of pigment in the skin. Darker pigmented individuals will normally emit a dark red or red-gray light whereas blonde or lighter pigmented individuals will have bright red or orange-yellow reflected light. The color and intensity of the light from the two pupils in one individual, however, should be symmetrical.
In 1962, Bruckner described abnormalities in the appearance of the quality, intensity, and symmetry of the light reflex from the two eyes as a screening tool. See Tongue A C, Cibis G W. Brückner test. Ophthalmology. 1981; 88:1041-1044, incorporated by reference herein. Subsequent authors have recommended the “Bruckner test” for clinically diagnosing misalignment of the eyes (strabismus), different sizes of the eyes (anisometropia), abnormal growths in the eye (tumors), abnormal opacities (cataracts, etc.) in the ocular media, and abnormalities in optic nerve transmission of light (i.e., asymmetrical pupil response).
In a 2010 publication from Israel, 11,500 normal newborn infants were screened with the red reflex test over a two year period. See Eventov-Friedman S, Leiba H, Flidel-Rimon O, Juster-Reicher A, and Shinwell E S. The red reflex examination in neonates: An efficient tool for early diagnosis of congenital ocular diseases. Is Med Assoc J 2010; 12:259-261, incorporated by reference herein. These authors detected congenital cataracts with an incidence of 1:2300. Although the sensitivity in this study was only 42%, the false positive was only 7/11,500 or 0.0006%. These authors recommend the use of a direct ophthalmoscopy test using the small hand-held ophthalmoscopes that are present in a wall-charger in most physicians' offices. For this test, the ophthalmoscope is set at 0 lens power, held close to the examiner's eye, and focused on each pupil of the patient individually at about 45 centimeters (cm) from the patient's eye. Both eyes are then viewed in quick succession. The red reflex seen in each eye should be similar. Dark spots in the red reflex, a blunted dull red reflex, lack of a red reflex, or presence of a white reflex are all indications for referral to an ophthalmologist. To maximize pupil dilation, the red reflex test is preferably performed in a darkened room. See The American Academy of Pediatrics, American Association of Pediatric Ophthalmology and Strabismus, and the American Academy of Ophthalmology. Eye examination in infants, children, and young adults by pediatricians. Pediatrics 2003; 111; 902-7, and American Academy of Pediatrics. Red reflex examination in neonates, infants, and children. Pediatrics 2008; 122; 1401-4, incorporated by reference herein.
The publication of the screening article from Israel discussed above led to the Israeli Pediatric Ophthalmology and Neonatal Societies mandating red reflex screening in Israel in 2010. The American Academy of Pediatrics (AAP), The American Association of Pediatric Ophthalmology and Strabismus (AAPOS), and the American Academy of Ophthalmology (AAO) all endorse the AAP's 2008 guidelines for pediatricians in performing the red reflex examination.
In spite of the practice guidelines published by the AAP, most pediatricians still do not adequately perform and document the red reflex examination, and there is no objective documentation in the medical record that the test was performed on a patient. There are two primary reasons that pediatricians fail to adequately detect the red reflex in infants and children: (1) the young child is often not attending to the pupillary illumination (the test subject must be looking directly at the light source for the testing to be successful), and (2) the pediatrician has only a fraction of a second to assess the pupillary reflex before the pupils constrict in response to the bright light from the ophthalmoscope.
Today, most pediatricians are not detecting treatable ocular pathology in a timely fashion because of the difficulty of red reflex testing with a direct ophthalmoscope. There is a need for overcoming these deficiencies discussed above and other reasons that this test is not being used. As will be appreciated, this invention addresses these deficiencies as well as others.
Another variation in the observation of the pupillary reflex, called eccentric photorefraction, is used to assess refractive error in children. Eccentric photorefraction uses a flash source that is eccentrically positioned relative to the camera aperture (Bobier W R, Braddick O J, Eccentric photorefraction: optical analysis and empirical measures. American Journal of Optometry & Physiological Optics, 1985; 62:614-620). A bright crescent appears in the pupillary reflex when the subject eye has sufficient hyperopia or myopia along the meridian of the flash eccentricity. There are existing instruments for performing eccentric photorefraction but they are not widely used due to their bulk and expense.
Another pediatric screening test is the Hirschberg test, in which corneal reflections of a broad-beam flashlight are used to detect strabismus. The drawback of the test is the lack of photographic documentation and quantitative measurement.